Abu Hurairah (RA) reported: I heard Allah's Messenger (ﷺ) as saying: He who saw me in a dream would soon see me in the state of wakefulness, or as if he saw me in a state of wakefulness, for the satan does not appear in my form.
Jabir reported Allah's Messenger (ﷺ) as saying: He who saw me in sleep in fact saw me, for it is not possible for the satan to appear in my form; and he also said: When any one of you sees a hulm (dream) he should not inform anyone, for it is a sort of vain sport of devil in the state of sleep.